The present invention relates to a method of reading out color image informations on an original script acquired in the form of a binary electric signal, and especially relates to a method of processing an image signal by reading out the image informations by means of a photoelectrical converter means, acquiring an analogue image signal and processing it binarily in order to obtain a binary color image signal.
As to reading out the image informations, in general, an image is focussed on the photo-sensing surface of a solid state image picking-up element by an optical system. However, there occur some problems that the high and low density distribution of the image or the space frequency causes the level of image signal read out to fluctuate and in consequence binary image processing at a high resolution turns out very difficult.